Today's distribution networks, such as cable distribution networks, can deliver a mix of video and data signals downstream to subscribers over a single RF output port. The video signals delivered may include both broadcast video signals and narrowcast video signals (e.g., video-on-demand signals). Although operators of distribution networks are now capable of sending these diverse types of signals (i.e., video and data) simultaneously over a single RF output port downstream to subscribers, the cost of such diverse data distribution remains relatively high.
For example, cable distribution networks generally employ two types of distinct devices for generating video and data signals; in particular, a cable modem termination system (CMTS) is generally used to generate and distribute data signals based on the DOCSIS standard and an edgeQAM (EQAM) is used to generate and distribute video signals. The signals from these two devices are combined and then transmitted downstream to subscribers. The need for two distinct devices to generate each type of signal is not cost effective in terms of the amount of equipment, power, and space needed. Moreover, these devices are typically limited in the number of channels they can produce and the ability to flexibly position each channel within a downstream RF signal spectrum.
Therefore, what is needed is a system for flexibly mapping input video and data streams to one or more output channels of a downstream RF signal, while reducing power, size, and cost requirements associated with prior implementations found in distribution networks.
The present invention will be described with reference to the accompanying drawings. The drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.